Control device



5. c. GRYCE CONTROL DEVICE Nov. 8, 1949 2 Shee'ts-Sheet 1 Filed Feb. 21, 1946 li- V Wan.

Y E. C. GRYCE CONTROL DEVICE Filed Feb. 21, 1946 2 Sheets-Sheet v 2 r INVENTOR.

JYTYUFNEY Patented Nov. s, 1949 CONTROL DEVICE Edwin C. Gryce, Bemidji, Minn.,

Minneapolis-Honeywell Regulator Minneapolis, Minn,

assignor to Company,

a corporation of Delaware Application February 21, 1946, Serial No. 649,349

15 Claims.

It is the purpose of my invention to provide control devices which have their elements so arranged that the devices will have improved operating characteristics.

It is an object of this invention to provide a flexible suspension and substantially frictionless pivot means for an actuated member of a control device wherein reed means having a relatively high spring rate is employed and having the elements of the pivot means so arranged that a relatively low spring rate is utilized in the operation of the control device.

It is another object of the invention to provide a flexible suspension and substantially frictionless pivot means for a movable element of a control apparatus which comprises a relatively long leaf spring means arranged with respect to stop means which permits small rotational movement of the movable element of the control apparatus and which also has an eilective spring rate that depends on the resiliency of the entire length of the leaf spring.

It is still another object of this invention to provide pivot means for an actuated member of a control device which combines the sensitivity of a relatively long reed means and at the same time obtaining the stability of a knife-edge pivot.

It is a further object of this invention to provide a substantially frictionless pivot means for an actuated member of a control apparatus which is durable in construction yet very sensitive in operation.

. Further objects will become apparent from the descript on and drawings forming a part of this specification.

For a more thorough understanding of this invention reference is made to the accompanying drawings in which:

Figure l is a top plan view oi. a control device embodying my novel pivot structure;

Figure 2 is a sectional view taken on line 2-2 of Figure 1;

Figure 3 is a sectional view taken on line 8-3 scale, of one of the suspension and pivot means for the armature, the armature shown actuated to the left. 8

Referring now to Figures 1 to 3,-inclusive, ll designates a mounting member preferably made of insulation material with a base member l2 of insulation material appropriately secured to the mounting member Ill. Suitable electrical terminals l4 and 16 are mounted in the base member 12. There is a compartment member it formed integral with the base member l2.

There is a bracket member 20 mounted on the base i2, and a bellows 22, carried on the bracket 20, is filled with a volatile fluid such as butane or iso-butane. An L-shaped lever 24 has one arm thereof engaging the plunger of the bellows 22. There is a knife edge member 26 associated with the bracket 20 about which the lever 24 pivots.

Also secured to the base I2 is an adjustment knob 28 mounted ,upon a post 29. The adjustment knob 28 carries an adjustment cam 30. An arm 82 is pivoted at 34 to the bracket 20 and the opposite end of the arm supports a roller 88 which is adapted to engage the cam member 30. A tension spring 38 is connected by screw means to the arm 32 and to the lever 24 intermediate their ehdS. I

A coil spring 40 extends through an aperture in the compartment i8 and is appropriately secured to the right-hand end of the lever 24. A resilient arm 42 is positioned in the compartment l8 and is provided with a downward extension 43 having a lateral portion 44. An insulation block 46 is secured to the lateral portion 44 and a screw means fastens the coil spring 40 to the insulation block 46. The coil spring 40 serves as a flexible connector between the resilient arm 42 and the lever 24. A'bracket 48 is secured by screws to a wall of the compartment l8 at its upper righthand end. A substantially U-shaped resilent leaf spring or reed member 50 comprising a pair of spaced apart laterally extending legs 5| and 52 is secured to the bracket member 48. The left end of the legs 5| and 52 of the leaf spring member 5|! are secured to the downward extension 48 of the resilient arm 42 by a plate member 55 and screws 54.

An abutment member 56 extends from a wall of the compartment l8 and is provided with a knife edge portion 58. The knife edge portion 58 of the butment 56 engages one side of the legs 5| and 52 of the leaf spring member 50. A resilient spring member 60 is secured to the bracket 48 and comprises depending arms 62 and 64 which are curved downwardly toward the resilient legs 5! and 52. Each arm 62 and 84 is provided with an angular portion 66, 66 respectively at its lower end. The angular portions 66, 68 of the arms 52 and 64 respectively are bent substantially at right angles with respect to the downwardly curved portion of these arms thereby forming knife edges 10 and 12. The knife edges 10 and 12 of the arms 62 and 64 resiliently engage a side of the legs and 52 respectively of the'leaf spring member 50 which is opposite the side on which the knife edge 58 abuts the legs 5| and 52. The knife edges and 12 of the arms 62 and 64 are tangent or in alinement in substantially the same plane on the legs 5| nd 52 of the leaf spring member 50 as the knife edge 58 of the abutment 56. The knife edges 10 and 12 engage one side of the legs 5| and 52 while knife edge 58 abuts the opposite side of the legs 5| and 52 and the knife edges 10-42 and 58 being in alignment thereby form a pivot means for the resilient arm 42,

A sliding contact 14 is carried by the resilient arm 42 and is adapted to slidably engage a resistance element or potentiometer 16 mounted on a bobbin 18 mounted in the left end of the compartment I8. Electrical conductors 80 and 82 extend from the opposite ends of the poten- 5| and 52, there is flexing or arching in the short portion of the legs 5| and 52 or that portion between the knife edges 10-12 and 58 and the resilient arm 42. .There is also flexing or arching in the relatively long portion of the legs 5| and 52 or that portion between the knife edges 10--12 and 58 and their point of connection with the bracket 48. The flexing in the long and short portions of the legs 5| and 52 both affect the operation of the slidable contact 14. When the arm 42 and its sliding contact 14 is actuated in either direction with respect to the potentiometer tiometer and are connected to the terminals I6--|6 in the base I2.

The knife edges 10 and 12 of the arms 62 and 64 respectively engage one side of the legs 5| and 52 adjacent their left ends while the knife edge 58 engages the opposite side of the legs 5| and 52 and the knife edge 58 is positioned to be in alignment with knife edges 10 and 12 thus dividing the legs 5| and 52 into short portions spaced between the knife edges and the resilient arm 42 while there is a relatively long portion of the legs 5| and 52 spaced between the knife edges and their point of connection to the bracket 40. The resilent arms 62 and 64 have sufficient tension so that the knife edges 10 and 12 respectively will always maintain the resilient leg members 5| and 52 in engagement with the knife edge 58 when the bellows 22 upon a change in the condition actuates the slidable contact 14 over the potentiometer 16 through means of the pivoted lever 24, flexible connection 40 and the resilient arm 42.

If the temperature decreases in the space wherein the instrument is mounted, the pressure in the bellows 22 will decrease and the bellows plunger will move toward the left and the lever 24 will pivot in a clockwise direction about the knife edge 26. The flexible connecting link 40 is then pulled downwardly, thus moving the lateral portion of arm 42 downwardly. The portion of the resilient arm 42 on the left side of the pivot is moved upwardly sliding contact 14 upwardly on the potentiometer 16, and the resilient legs 5| and 52 secured to the resilient arm 42 pivot the arm 42 about the knife edges 10-12 and the knife edge 58 (see Figure 1). The knife edges 10, 12 and 50 being spaced adjacent the left end of the leaf springs legs 5| and 52 provide a substantially fixed pivot for arm 42 which will transmit equal increments of move ment from the bellows 22 to the slidable contact 14. The knife edges 10 and 12 of the resilient arms 62 and 64 respectively are so spaced relative to the knife edge 58 as to permit a limited movement to the legs 5| and 52 0f the leaf spring member 50 when the arm 42 is actuated by the bellows 22. During the movement of the legs 16, the flexing or arching adjacent the knife edge 58 is in the same direction in both the short and long portions of the legs 5| and 52. The short portion of the legs 5| and 52 has a relatively high spring rate while the long portion of the legs 5| and 52 has a relatively low spring rate, and with a pivot structure which permits movement of the legs 5| and 52, the 'combined spring rates of the short and long portions of the legs 5| and 52 affect the operation of the slidable contact 14. This pivot construction combines the stability of a fixed pivot and the sensitivity of a relatively long flexible spring member.

It is necessary to utilize a relatively thick or rugged leaf spring member so that the same will not break during assembly of the device or during the operation of the control device. By employing a relatively fixed pivot structure at one end of a relatively long leaf spring member, which permits movement for the leaf spring member, it is possible to utilize a very rugged leaf spring member and at the same time obtain a relatively low spring rate pivot for the slidable contact 14.

Adjustm nt of the knob 28 in a counterclockwise direction rotates the higher portion of the cam 30 for engaging the roller 36 and this adjustment moves the pivoted arm 32 downwardly as disclosed in Figure l of the drawings, increasing the tension of the spring 38. The increased tension on the spring 38 will adjust the slidable contact 14 on the potentiometer 16 through means of the lever 24, interconnecting link 40 and the resilient arm 42 with respect to a given value of the condition to which the bellows 22 responds. The bellows 22 responds to temperature changes, thus the temperature setting of the device will be varied by change of tension of the spring 38.

The relay as disclosed in Figures 4 to 8 inclusive, of the drawings is contained within a housing 99 made up of a rear portion or enclosure I00 and a cooperating front portion or enclosure I02. When the two portions I00 and I02 of the housing 99 are assembled together, angular portions I08 and II 0 of the portion I02 overlap with angular portions I04 and I06 of the portion I00. Screws secure the angular portions I04 and I08 to a bracket H2 and screws secure the angular portions I06 and M0 to a bracket H4. The brackets H2 and H4 are mounted upon an insulation base II6.

Mounted in the housing 99 is a pair of spaced coils H8 and I20. An armature is designated at I22. Located at opposite ends of the armature I22 are upwardly extending cores I24 and I26 which coact with the coils H8 and I20, respectively. An aperture I 25 is formed in core I24 of the armature I22 below the center of the coil II8, while an aperture I21 is formed in the core I26 of the armature I22 above the center of the coil I 20. The sizes of the apertures I25 and I21 are equal and their moment arms from games have their lower ends secured between the cross bars I28 and I30 carried by the armature I22.

There is a switch blade I42, one end of which is attached to the armature I22 and the free end having spaced contacts I44 and I46. Terminal brackets I48 and I50 extending from the base II6 carry adjustable screws I52 and I54 respectively, each of which have contacts for cooperating with the contacts I44 and I46 on the switch blade I42.

An adjustable bracket I56 is mounted on the rear portion I of the housing 38 and a spring finger I58 is secured to the adjustable bracket I56. The finger I58 is provided with an angular portion I60 at its lower end. The angular portion I60 is bent with respect to a depending portion of the spring finger I58 to form a knife edge I62. There is an adjustable bracket I64 extending from the front portion I02 of housing 09. A spring finger I65 is secured to the bracket I64 and is formed with an angular portion I66 at its lower end which is bent with respect to a depending portion of the spring finger I65 to form a knife edge I68. The knife edge I62 and the knife edge I68 respectively abut a side of the legs I38 an I40 of the U-shaped leaf spring member I34 acjacent their lower ends. There is a hexagcnal bracket I adjustably mounted in the rear portion I00 of the housing. The hexagonal bra :et I10 is spaced so that a portion thereof is adapted to cooperate with a side of the leg I38 of the U-shaped spring member I34. The hexagonal bracket I10 cooperates with one side of the leg I33 while the knife edge I62 engages the opposite side of the leg I38, with the abutting portion of the hexagonal bracket I10 being in alignment with the knife edge I62. A hexagonal bracket I12 is adjustably mounted in the front portion I02 of the housing 99 and a portion thereof abuts a side of the resilient leg I40 of the U-shaped leaf spring member I34 which side is opposite the side on which the knife edge I68 of the spring finger I65 abuts the le I40. The abutting portion of the bracket I12 is in alignment with the knife edge I68.

The knife edge I62 and the abutting portion of bracket I10, knife edge I68 and the abutting portion of bracket I12 coacting with legs I38 and I40 respectively provide a fulcrum or pivot I6I about which the armature I22 rotates. Knife edge I62 and bracket I10, and the knife edge I68 and bracket I12, are positioned adjacent the lower end of the legs I38 and I40'respectively, dividing the legs I38 and I40 into a relatively short portion between the fulcrum point and the armature I22 and a relatively long portion between the fulcrum point and the bracket I32. If either coil H8 or coil I were energized, then the armature I22 would be rotated in either a clockwise or a counterclockwise direction and the legs I38 and I40 secured to the armature I22 would pivot the armature I22 about the knife edge I62 and bracket I10, and knife edge I68 and bracket I12. Since the portion of the legs I33 and I40 between the pivot and the armature I22 is relatively short. the armature will have a small lateral movement and as a consequence a smaller air gap is required for the coils H3 and I20. When a smaller air gap is used for the coils then a greater iiux density is obtained which results in a more sensitive relay. When. the armature I22 is rotated the knife edges I62 and I66 are so spaced with relation to the brackets I10 and I12 respectively that a longitudinal movement is permitted to the legs I36 and I40. The relatively short portion of the legs I38 and I40 between the fulcrum point and the armature and the relatively long portion of the legs I33 and I43 between the fulcrum point and the bracket I32 will both flex along the same curvature or in the same direction and the spring rate of the entire length of the legs I38 and I40 affects the operation of the armature I 22 (see Figure 8).

In the construction of the present relay it is necessaryto make a device which is sensitive in operation and which is also sufficiently rugged so that it can be quickly assembled without the breakage of parts and which will have long life in operation. Therefore, it is necessary to employ a relatively thick leaf spring member such as member I34 so that the part can be easily assembled without danger of breaking. Where the knife edges I62 and I68 are positioned on one side at the lower end of the relatively long and thick leaf spring legs I38 and I40 respectively adjacent the armature I22, and where a portion of the brackets I10 and I12 engage the opposite side of the legs I38 and I40 in alignment with the knife edges I62 and I68 respectively, with the knife edges I62 and I68 being in such spaced relationship with respect to the brackets I10 and I12 as to permit longitudinal movement to the legs I33 and I40, a substantially frictionless pivot is provided which is rugged in construction but yet sensitive in operation.

The knife edge I62 and the engaging portion of the bracket I10, the knife edge I68 and the engaging portion of the bracket I12 must be tangent at the same point on the legs I38 and I40 respectively of the leaf spring suspension member I34 so as to provide an equal spring rate for movement of the armature I22 in either direction of rotation. when the knife edges and the engaging portions of the bracket are tangent on the legs I38 and I40, no binding of the legs I38 and I40 will occur between the knife edges and brackets to restrict longitudinal motion of the leg members. It is possible to maintain the knife edge I62 and the engaging portion of the bracket I10 tangent at the same point on leg I38 by adjusting the brackets I56 and I10, respectively. It is likewise possible to maintain the knife edge I68 and the engaging portion of the bracket I12 tangent at the same point on the leg I40 by adjusting the brackets I64 and I12, respectively. I

The resilient legs I36 and I40 are used as electrical connectors between the electrical terminals I48 and I50 and the electrical terminal I32, thus eliminating the need for pigtails.

When the relay is unenergized, the spring legs I38 and I40 are in an unstressed condition, and

switch blade I42 is located midway between the fixed contacts carried by the screws I52 and I54, and this is due to the fact that the moments of the left-hand and right-hand portions of the armature about the effective pivot I6I are equal. This equality of the left-hand and right-hand portions of the armature I22 is provided by making the armature assembly itself symmetrical and also by so selecting the sizes andthe moment arms of apertures I25 and I2! so that their moments about the effective pivot I6I are also equal.

Upon equal energization of coils II 8 and I20, which is the normal condition of the coils, however a counterclockwise torque about pivot I6I is applied to the armature I22. This counterclockwise torque of the armature I22 about pivot IGI is introduced because apertures I25 and I2! are on opposite sides of the centers of their respective coils, so that the magnetic force acting upon core I24 is essentially downward, while the magnetic force acting upon core I26 is essentially upward. When the armature I22 is moved in a counterclockwise direction by the magnetic unbalance of the relay, switch blade I42 is caused to be displaced so that electrical connection is made between contact I44 and the contact carried by the screws I52, and which movement stresses spring legs I38 and I40.

In adjusting the relay for use, after the coils H8 and I20 have been equally energized, bracket I32 is rotated in a counterclockwise direction so as to apply a force to the spring legs I38 and I40 opposing the force placed on the legs I38 and I40 due to equal energization of coils II8 and I20.

When the mechanical bias is applied to the armature I22 through means of legs I38 and I40 which is just suiiicient to overcome the bias applied to the armature I 22 due to the equal energization of the coils H8 and I20, the switch blade I42 is returned to its central position between the contacts carried by the screws I52 and I54.

It will now be apparent that upon deenergization of the coils H8 and I20 by power failure, the mechanical bias of the armature I22 introduced by the counterclockwise rotation of bracket I32 is no longer opposed by the bias on the armature I22 provided by the coils II 8 and I 20 acting on the cores I24 and I26, and the armature I22 will be actuated in a clockwise direction so that switch blade I42 completes electrical connection between contact I46 and the contact carried by screw I54. When the circuit is completed between contact I46 and the contact carried by the screw I 54, a controlled device will be moved to a safe position.

It is seen from the above description that I have provided control devices of novel construction which are extremely sensitive and accurate in operation and which are easy and inexpensive to manufacture.

While two embodiments of this invention have been shown and described, it is obvious that many modifications may be apparent to those skilled in the art and consequently this invention is to be limited only by the scope of the appended claims and the prior art.

I claim as my invention:

1. In a control device of the class described, comprising, in combination; a member adapted to be moved, a lever actuated thereby, an arm connected to the lever, and pivot means for the arm, the pivot means comprising leaf spring suspension means and cooperating abutment means to provide a frictionless pivot for the arm.

2. In a control device of the class described, comprising, in combination. a member adapted to be moved in response to condition changes, a lever actuated thereby, an arm connected to the lever, and pivot means for the arm, the pivot means comprising leaf spring suspension means for the arm and cooperating abutment means spaced on opposed sides of the leaf spring means adjacent where the leaf spring means is attached to the arm for providing a frictionless pivot means. a

3. In a control device of'the class described, comprising, in combination, a member adapted to be moved in response to condition changes, a lever actuated thereby, an arm connected to the lever, and pivot means for the arm, the pivot means comprising leaf spring suspension means secured to the arm and having a stationary abutment located on one side and a yieldable abutment spaced on the opposite side for providing a frictionless pivot means.

4. In a control device of the class described, comprising, in combination, a member adapted to be moved in response to condition changes, a lever actuated thereby, an arm connected to the lever, and a substantially frictionless pivot means for the arm, the pivot means comprising leaf spring suspension means secured to the arm and cooperating abutment means spaced adjacent one end of the leaf spring suspension means and being so arranged with respect to the leaf spring means as to utilize the spring rate of substantially the entire length of the leaf spring suspension means.

5. In a control device of the class described comprising, in combination, a member adapted to be moved, a lever actuated thereby, an arm connected to the lever, a support member, and a substantially frictionless pivot means for the arm, the pivot means comprising a relatively long leaf spring suspension means having a relatively high spring rate per unit length secured between the support member and the arm and abutment means spaced on opposed sides of the leaf spring means adjacent where the leaf spring means is secured to the arm dividing the leaf spring means into a relatively short portion between the abutment means and the arm and a relatively long portion between the abutment means and the support member, the abutment means being so arranged with respect to the leaf spring means as to permit longitudinal movement of the leaf spring means when the arm is actuated, thereby utilizing the spring rate of both the short and long portions of the leaf spring means.

6. In a device of the class described, comprising, in combination, support means, a control device, an arm associated with the control device, reed suspension means connected between the support means and the arm, abutment means associated with the reed means dividing the reed means into a short portion between the abutment means and the arm and a relatively long portion between the abutment means and the support means, and means for actuating the arm with respect to the control device, the reed means rotating about the abutment means and utilizing the resilience of both the short and long portions of the reed means to provide a sensitive movement for the arm.

7. In a device of the class described, comprising, in combination, support means. a control device, an arm associated with the control device, reed suspension means connected between the support means and the arm, and abutment means associated with the reed means providing a pivot for the arm, the abutment means permitting limited longitudinal movement for the reed means when the arm is actuated.

8. In a control mechanism of the class described, comprising, in combination, a device to be operated, a member associated with the devic to be operated for controlling the operation of the device, flexible means supporting the member,

and an abutment means associated with the flexible supporting means providing a pivot for the member, the abutment means permitting longitudinal movement of the flexible supporting means when the member is actuated.

9. In a control mechanism of the class described, comprising, in combination, a device to be operated, a member associated with the device to be operated for controlling the operation of said device, flexible means supporting the member, and an abutment means associated with the flexible supporting means adjacent the member providing a pivot for the member, the abutment means permitting longitudinal movement of the flexible supporting means when the member is actuated.

10. In a control mechanism or the class described, comprising, in combination, a device to be operated, a member associated with the device to be operated for controlling the operation of said device, a support means, reed means connected between the support means and the member, and an abutment means associated with the reed means adjacent the member for providing a pivot for the member, the abutment means viding the reed means into a. relatively short portion between the abutment means and the member and a relatively long portion between the abutment means and the support means, the abutment means permitting longitudinal movement of the reed means when the member is actuated.

11. In a sensitive device, a support, an arm to be positioned, a pivot for said arm comprising-a resilient reed carried at one end by said support and carrying said arm at its other end, and means carried by said support engaging said reed at a point remote from its point of connection to said support, said means preventing lateral movement of the portion of said reed so engaged but permitting longitudinal movement thereof.

12. In a mechanical linkage, a support, a memher having a flexible reed like portion fixed to said support, and means carried by said support engaging said member at a point remote from the connection of said flexible portion to said support, said means preventing lateral movement of the portion of said member so engaged but permitting longitudinal movement thereof.

13. In a sensitive device, a support, an arm to be positioned, a pivot for said am comprising a resilient reed carried at one end by said support and carrying said arm at its other end, a rigid abutment carried by said support engaging one side of said reed at a point remote from the connection of said reed to said support, and a resilient abutment biasing said reed against said rigid abutment.

14. In a sensitive device, a support, a reed carried by said support, an arm to be positioned secured to said reed a substantial distance from the connection of said reed to said support, means carried by said support engaging said reed adiacent the connection between said reed and said arm for preventing lateral displacement thereof but permitting longitudinal movement thereof, and means for actuating said arm.

15. In a sensitive device, a support, a member having a rigid portion and a flexible extension the extremity of which is attached ti) said support, a rigid abutment carried by said support and engaging one side of said member at a point remote from the connection of said ,member to said support, and a resilient abutment biasing said member laterally against said arigid abutment, said abutments establishing a piv'otal axis for the rigid portion of said member on said support.

EDWIN C. GRYCE.

' REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Liner Niay 19, 1942 

